1. Field of the Invention
The invention relates to a data processing apparatus, and more particularly to a system for starting-up an extension connected to the data processing apparatus and including therein BIOS code having architecture different from architecture of a central processing unit.
Herein, BIOS is short for "Basic Input Output System", and is a program for implementing initialization and start-up.
2. Description of the Related Art
In a conventional data processing apparatus including an external extension in which BIOS code having an architecture different from an architecture of a central processing unit (hereinafter, central processing unit is referred to simply as "CPU") is mounted, when the extension is to be started-up during a system is being booted, it was necessary for a system firmware stored in a memory such as a read only memory (ROM) to be provided with the same functions as those of BIOS code, or be provided with an emulation function by which a machine language having a different architecture is converted into a machine language readable by CPU.
Japanese Unexamined Patent Publication No. 8-286996 having been published on Nov. 1, 1996 has suggested a driver for driving an extension in which BIOS code having an architecture different from an architecture of CPU is mounted, and which is electrically connected to a data processing apparatus. When the extension is to be started-up during a system is being booted, an emulator mounted in an operation system is used to thereby emulate a code of the extension to the same code of CPU, whereby starting-up the extension.
The above-mentioned drive system wherein it is necessary for a system firmware stored in a memory such as a read only memory (ROM) to be provided with the same functions as those of BIOS code, or be provided with an emulation function by which a machine language having a different architecture is converted into a machine language readable by CPU, is accompanied with a problem of poor system development efficiency and an increase in usage of ROM. This is because too many functions are necessary to be mounted in a system firmware.
The driver suggested in the above-mentioned Japanese Unexamined Patent Publication No. 8-286996 has improved a system development efficiency, and reduced usage of ROM. However, the driver is accompanied with another problem that when an extension which has a lot of kinds of BIOS codes and is electrically connected to an operation system is to be started-up during a system is being booted, BIOS codes have to be emulated each time when the operation system is started-up. This results in waste of time necessary for starting-up the operation system.